Angry Birds IPO fails to take off

Investors have cried foul on the Angry Birds IPO.

Shares in Rovio Entertainment, the Finnish company behind Angry Birds, traded as much as 5% below their initial price of €11.50 ($13.50) on Tuesday.

The mobile gaming firm, which listed on the Nasdaq Helsinki, is now valued at just over $1 billion.

Hannu Verkasalo, founder of digital behavior consultancy Verto Analytics, said that investors had been excited by Rovio's status as a new 'national stock' in Finland, like Nokia was a decade ago.

The company's hit game series -- Angry Birds -- has been downloaded over 3.7 billion times. But other investors are worried about its ability to churn out new hit games.

Richard Holway, chairman of TechMarketView, said the fear is that Rovio will turn out to be another "one-hit wonder."

Other hit gaming companies serve as cautionary tales.

King Digital Entertainment, the company behind Candy Crush, targeted a $7 billion valuation when it went public in 2014. But the company disappointed investors after its other games didn't become hits.

The game maker was purchased last year by Activision for $18 a share -- 20% bellow its IPO price.